My life as a reborn monster - Chapter 8 - Just Call Me Lucky

"Locke transmigrated into an era where everyone had Battle Beasts. Daemons were rampant and humans were forced to build walls around their dwellings while depending on Beastmasters to keep those monsters at bay.

Astra woke up in a forest with no recollection of her precious life.The only thing she knew was that she had a system with two parts; one was a Survival System, and the other was a...Wait, what?!A Breeder System?!

The plague of insects descended overnight. As an ordinary person without invincible powers and extraordinary exercises, facing blood and death, what should we do at the critical moment of life and death?

(I am a reasonable party, but the novel needs appropriate YY, please do not excessively investigate the rationality of the background in a razor-sharp way.)

- Description from novelbuddy

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.